| abstract |
PURPOSE: To obtain in high productivity low-hygroscopic Na 2 Si 2 O 5 with high ion exchange ability by adding a specified amount of aluminum and/or boron component(s) to a sodium silicate solution of specified composition followed by baking. n CONSTITUTION: A solution of sodium silicate with the molar ratio SiO 2 /Na 2 O being 1.9-3.2 is incorporated with 0.5-2mol%, based on the Si, of an aluminum and/or boron component(s) followed by homogenization. The resulting solution is then baked and crystallized through such a process as to introduce it into a heating zone held at a state of crystallization temperature range, thus obtaining the objective modified disodium silicate. The aluminum source to be added is pref. sodium aluminate or soluble aluminate, while the boron source, pref. boric acid or borax. The present modified disodium silicate can be suitably used as e.g. a raw material for builders to be used in synthetic detergents. n COPYRIGHT: (C)1992,JPO&Japio |